body {
            font-family: 'Segoe UI', Arial, sans-serif;
            line-height: 1.6;
            background-color: #f4f4f4;
            color: #333;
            margin: 0;
            padding: 0;
        }

        header {
            background-color: #02489e;
            color: white;
            padding: 20px;
            text-align: center;
        }

        .tab-nav {
            overflow: hidden;
            background-color: #333;
            border-bottom: 3px solid #02489e;
        }

        .tab-nav button {
            background-color: inherit;
            float: left;
            border: none;
            outline: none;
            cursor: pointer;
            padding: 14px 16px;
            font-size: 17px;
            color: white;
            transition: 0.3s;
        }

        .tab-nav button:hover {
            background-color: #555;
        }

        .tab-nav button.active {
            background-color: #02489e;
        }

        main {
            padding: 20px;
            max-width: 800px;
            margin: 20px auto;
            background-color: #fff;
            border-radius: 8px;
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }

        .tab-content {
            display: none;
            padding: 10px;
            border-top: none;
        }

        input[type="text"], input[type="number"] {
            width: 90%;
            padding: 10px;
            margin: 10px 0;
            border: 1px solid #ccc;
            border-radius: 4px;
        }

        button {
            background-color: #02489e;
            color: white;
            padding: 10px 15px;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            margin: 5px 2px;
        }

        button:hover {
            background-color: #02489e;
        }

        .kalkulator-container button {
            width: 48px;
            height: 48px;
            font-size: 20px;
        }

        #hasilKalkulator {
            font-size: 1.5rem;
            font-weight: bold;
            color: #333;
            margin-top: 15px;
        }

        #daftarBelanjaList {
            list-style-type: none;
            padding: 0;
            margin-top: 20px;
        }
        #daftarBelanjaList li {
            padding: 12px;
            background: #f9f9f9;
            border-bottom: 1px solid #ddd;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        #daftarBelanjaList li:nth-child(odd) {
            background: #f1f1f1;
        }
        #daftarBelanjaList button {
            background-color: #f44336;
            padding: 5px 10px;
            font-size: 12px;
        }
        #daftarBelanjaList button:hover {
            background-color: #d32f2f;
        }

        .jam-container {
            text-align: center;
            background-color: #2c3e50;
            color: #ecf0f1;
            padding: 30px;
            border-radius: 10px;
        }
        #jamDigital {
            font-size: 4rem;
            font-weight: bold;
            letter-spacing: 2px;
        }
        #kalender {
            font-size: 1.5rem;
        }

        .quiz-container {
            padding: 15px;
        }
        #soalQuiz {
            font-size: 1.3rem;
            margin-bottom: 20px;
        }
        #opsiQuiz button {
            display: block; 
            width: 100%;
            background-color: #f1f1f1;
            color: #333;
            text-align: left;
        }
        #opsiQuiz button:hover {
            background-color: #ddd;
        }
        #hasilQuiz {
            font-size: 1.5rem;
            font-weight: bold;
            text-align: center;
            margin-top: 20px;
        }